Hewa Kondaramage Rasika Sampath Kumara, Keerthi Sri Senarathna Atapaththu, Sandamali Sakuntala Herath
et al.
Integrated rice-fish farming (IRFF) is a promising agronomic strategy that enhances crop and fish productivity while improving soil health and resource use efficiency. This study aimed to assess the effects of different rice planting spacing on the growth and yield of rice and fish and evaluate soil fertility and water quality within an IRFF system. A field experiment was conducted using four (T1–T4) planting spacing; T1: 10 cm × 10 cm, T2: 15 cm × 15 cm, T3: 20 cm × 20 cm, and T4: 25 cm × 25 cm. Each treatment with three replicates was randomly allocated in a randomized complete block design. Growth and yield parameters of rice and fish were measured along with soil and water quality indices. Data were analyzed using ANOVA and Tukey’s test. Spacing influenced both rice and fish performance significantly. The 15×15 cm spacing provided the best balance, supporting high yields for both rice and fish without adverse effects on soil fertility or water quality. Narrower spacing enhanced total rice yield through higher plant density but reduced individual plant performance. Wider spacing improved individual plant growth yet lowered total yield. Soil nutrient levels (N, P, and K) and organic matter (OM) significantly increased across treatments, with T2 showing the highest enrichment. Water quality parameters (pH, EC, temperature, DO, NO3–, NH3) remained within non-toxic limits. This study suggests that 15×15 cm spacing optimizes rice-fish yields and enhances soil quality without compromising water quality in IRFF systems.
Non-grain plant raw material palm meal can replace the limited grain raw material, which can provide a certain reference for aquaculture to reduce the cost and reduce the dependence on grain raw material. A 12-week feeding trial was conducted to evaluate the effects of substituting wheat bran with palm kernel meal (PKM) on the growth performance and intestinal health of grass carp (Ctenopharyngodon idellus). Six isoproteic (crude protein 32 %) and isolipidic (crude lipid 6 %) diets were formulated, incorporating varying levels of PKM replacing wheat bran: 0 % (PKM0), 20 % (PKM20), 40 % (PKM40), 60 % (PKM60), 80 % (PKM80), and 100 % (PKM100). Juvenile grass carp, with an initial body weight of 7.14 ± 0.04 g, were fed twice daily to satiation. The results indicated that PKM could completely replace wheat bran without compromising the growth performance of grass carp, with optimal growth observed at 40 % replacement level. High substitution levels (≥40 %) significantly increased intestinal trypsin and amylase activities, but decreased plasma contents of lipopolysaccharide, D-lactic acid, and endothelin-1. Partial substitution of wheat bran with PKM (2040 %) significantly upregulated the relative expression of zo-1 and occludin in midgut, whereas higher replacement levels (40100 %) generally upregulated the relative expression of tgf-1 and il-10. Similarly, high replacement levels (≥60 %) generally increased the contents of intestinal mucin 2, complement 4 and immunoglobulin M. In conclusion, the complete substitution of wheat bran with PKM did not adversely affect the growth performance of grass carp, with optimal growth occurring at 40 % replacement level. Additionally, high substitution levels (≥40 %) generally improved intestinal health by enhancing digestive enzyme activity, reducing intestinal mucosal permeability, and mitigating intestinal inflammatory responses.
The physical properties of stellar atmospheres in rapidly rotating massive stars, such as Be stars, are critical to understanding their evolution and their role as progenitors of supernovae. These stars, which often have near-critical rotation, exhibit equatorial stretching and gravity darkening, which significantly complicates the determination of parameters such as the inclination angle. Be stars, characterized by their extreme rotational velocities, serve as excellent candidates for exploring these phenomena. However, fundamental quantities such as polar and equatorial radii and inclination angles are typically derived from interferometry, which applies only to a limited number of stars. This study aims to enhance the determination of inclination angles for Be stars using the ZPEKTR spectral synthesis code. By incorporating advanced models of gravity darkening and stellar deformation, we evaluated the effectiveness of this method with a sample of ten Be stars from the BeSOS database, comparing results with established interferometric data. Methods. We used the ZPEKTR code to model the effects of stellar oblateness and gravity darkening on spectral lines, focusing on the HeI 4471 line. We applied a chi-squared test minimization approach to identify the best-fitting models, and we evaluated the inclination angles derived against interferometric measurements. Our analysis reveals a robust linear correlation between the inclination angles derived from ZPEKTR and using interferometric techniques, which demonstrates an excellent agreement. The ZPEKTR code effectively models high rotational velocity effects, providing precise stellar parameter determinations. The results underscore the potential of advanced spectroscopic techniques to yield inclination measurements comparable to interferometry, which offers a pathway to studying distant massive stars.
Skin colour is an important criterion in determining the aesthetic appeal of ornamental fishes, and thus their market worth. Hence the pigment enhancement in ornamental fishes has been the subject of extensive research by using various synthetic as well as natural pigment sources. Dietary composition is one of the most important elements that influence the development of pigmentation in fish. This study is an attempt to assess the possibility of using carotenogenic marine yeast as pigment enhancer in fish diet for Koi carp, Cyprinus carpio. The 60 days feeding experiment was done by using feed incorporated with mangrove associated marine yeast Rhodotorula paludigena VA242. Greater pigmentation in the scales of fishes fed with experimental feed was observed than that fed with the control diet (normal pellet feed). Furthermore the improved growth rate and general wellbeing in fishes fed with experimental feed provides scope for further studies in this field with respect to the growth and survival of fishes.
Solomon Wagaw, Ayalew Sisay, Asnaku Bazezew
et al.
Biometric evaluation and reproductive biology of Oreochromis niloticus were studied from Geray Reservoir. Between November 2021 and August 2022, 316 O. niloticus specimens were collected from this reservoir. The observed male to female sex ratio was 1:1.14, which was statistically insignificant compared with the hypothetical 1:1 sex ratio (X2 = 1.27, p > 0.05). The length-weight relationship was curvilinear with allometric growth (b < 3) and statistically significant from the expected isometric growth pattern (b = 3). The regression equation for females was TW = 0.0264TL2.72 (r2 = 0.90, n = 168), males (TW = 0.0183TL2.79, r2 = 0.93, n = 148), and combined sexes (TW = 0.0229TL2.76, r2 = 0.91, n = 316). Gonadosomatic index (GSI) ranged from 0.8 to 1.4 (males) and 1.8 to 4.9 (females). The breeding season lasted from March to June, with a GSI peak in April. Fecundity ranged from 279 to 1,528 eggs./fish, with a mean of 1,025 eggs./fish. The correlation between absolute fecundity and length was more significant (F = 0.76TL2.8, R2 = 0.94, p < 0.05) than with weight (F = 17.683TW0.71, R2= 0.92, p < 0.05). This study provides basic information on the biology of O. niloticus in the Geray Reservoir for future fishery management tools for the conservation and utilization of this valuable freshwater fish.
Filamentous algae are present in seawater and freshwater ecosystems worldwide. Their growth poses a serious threat to water environments and fishery production, especially Chinese mitten crab and red swamp crayfish culturing. To explore safe and ecological treatment methods, we comparatively studied the grazing effects of Xenocypris davidi Bleeker on Cladophora (one species) and Spirogyra (two species) in indoor glass tanks and examined the intestinal microbiota related to digestion and absorption. The results showed that the fish was more receptive to Spirogyra than to Cladophora, and the intake rates of different species of Spirogyra varied. Fish weight increased slightly after feeding with Spirogyra, and the levels of total nitrogen and total phosphorus in water increased significantly ( p < 0.05 ) relative to the initial values. Intestinal microbiota diversity and richness varied after feeding with three filamentous algal species, and the similarity increased after feeding with two Spirogyra species. The microbial species detected in this study belonged to 40 phyla and 838 genera. The clustering characteristics of different groups and subgroups were obvious based on the microbial phylum composition. Significant differences in the relative abundance rates of eight nutrition-related metabolism functions were found among groups and subgroups ( p < 0.05 ). The correlations between intestinal microbiota and metabolism functions were analyzed, and some meaningful correlations were revealed. The results presented in this study provided a meaningful reference on the control of the overgrowth of filamentous algae in aquaculture waters by the biomanipulation method.
Udang Vannamei litopenaeus vannamei berkembang pesat dengan teknologi intensif sehingga dapat ditebar dengan kepadatan yang lebih tinggi dan memiliki sintasan serta produksi yang tinggi. Ekstrak bawang putih dapat meningkatkan hematologis udang Vannamei, efisiensi pemanfaatan pakan, kelulusan hidup, dan kualitas air yang baik untuk mendapatkan dosis yang tepat dari ekstrak bawang putih untuk menunjang imunitas udang Vannamei. Penelitian ini dilaksanakan pada bulan April sampai bulan Juni 2023 di Balai Perikanan Budidaya Air payau Takalar. Penelitian ini menggunakan rancangan acak lengkap (RAL) dan setiap faktor diulang sebanyak 3 kali. Hasil Penelitian menunjukkan hemosit udang awal sebesar 4.56 x 10.6 rata hemosit akhir 1,00 x 10 7 - 2,57 x 107, efisiensi pakan yang terbaik sebesar 5.08% nilai 0.44 (FCR). Dosis yang terbaik 10% ekstrak bawang putih dari 1 kg pakan, total kelulusan hidup sebesar 91% (41 ekor) dari total udang Vannamei pada perlakuan B.10% (45 Ekor). Vannamei shrimp Litopenaeus vannamei is growing rapidly with intensive technology, so it can be stocked at higher density, and it has high survival and production. Whether garlic extract improve the hermatology of Vannamei shrimp, feed utilization efficiency, survival and good water quality, to get the right dose of garlic extract to support Vannamei shrimp immunity. This research was carried out in April-June 2023, at the Takalar Brackish Water Aquaculture Fisheries Center. This study used a completely randomized design (CRD) and each factor was repeated 3 times. 1,00 x 10 7 - 2.57 x 107 , the best feed efficiency is 5.08% value 0.44 (FCR), the best dose is 10% garlic extract from 1 kg of feed, the total survival rate is 91% (41 heads) of the total shrimp Vannamei on treatment B.10% (45 head).
Dietary high soybean oil (SO) inclusion leads to excessive hepatic lipid accumulation and metabolism disorder in fish species. This study was conducted to investigate the effects of adenosine 5’-monophosphate-activated protein kinase (AMPK) pathway activation by acadesine (AICAR) on hepatic histology and metabolism-related gene expression of juvenile large yellow croakers (Larimichthys crocea) fed with SO-based diet. In this study, fish (initial body weight 3.89 ± 0.02 g) were fed fish oil (FO)-based, SO, or SOA (SO diet supplemented with 100 mg kg−1 AICAR) diets with three replicates of each treatment for 70 days. In general, the replacement of dietary FO with SO led to excessive hepatic lipid accumulation and a glucose metabolism disorder. Histological sections and biochemical analysis of hepatic tissue consistently revealed that AICAR supplementation could partly ameliorate SO-induced excessive hepatic lipid accumulation, probably by suppressing the expression of genes related to fatty acid uptake and lipogenesis while enhancing the expression of lipolysis-related genes. Nevertheless, AICAR regulated lipid metabolism in muscle tissue in an inverse pattern to that in hepatic tissue, indicating that muscle tissue could attempt to mitigate lipid accumulation by improving lipolysis in response to the dietary inclusion of SO. Dietary AICAR partly improved glucose metabolism by reducing the expression of genes related to gluconeogenesis in hepatic tissue while increasing the expression of genes related to glucose uptake and glycolysis in muscle tissue. Collectively, dietary AICAR mitigated excessive hepatic lipid accumulation and glucose metabolism disorder. The amelioration of hepatic lipid accumulation by AICAR is likely caused by increasing lipid catabolism and decreasing lipid anabolism. The improved glucose metabolism by AICAR may be ascribed to decreased hepatic gluconeogenesis, as well as increased muscle glucose uptake and utilization.
Mass-angle distribution (MAD) measurement of heavy and superheavy element fragmentation reactions is one of the powerful tools for investigating the mechanism of fission and fusion process. MAD shows a strong correlation between mass and angle when the quasi-fission event is dominant. It has characteristic that appears diagonal correlation as long as the quasi-fission event is dominant. This diagonal correlation could not be reproduced in previous our model before the introduction of the parameters. In this study, we systematically evaluate the unknown model parameters contained in our model and clarify those model parameters to reproduce the diagonal correlation that appears in MAD. Using a dynamical model based on the fluctuation dissipation theorem that employs Langevin equations, we calculate MADs of two reaction systems $^{48}$Ti+$^{186}$W and $^{34}$S+$^{232}$Th which are dominated by quasi-fission. We were able to clarify the effects of unknown model parameters on the MAD. In addition, we identified the values of model parameters that can reproduce the correlation between mass and angle. As a result, it was found that the balance of tangential friction and moment of inertia values is important for the correlation between mass and angle.
In this study, we propose a method to find an optimal central angle in deep learning-based depth map estimation used to produce realistic holographic content. The acquisition of RGB-depth map images as detailed as possible must be performed to generate holograms of high quality, despite the high computational cost. Therefore, we introduce a novel pipeline designed to analyze various values of central angles between adjacent camera viewpoints equidistant from the origin of an object-centered environment. Then we propose the optimal central angle to generate high-quality holographic content. The proposed pipeline comprises key steps such as comparing estimated depth maps and comparing reconstructed CGHs (Computer-Generated Holograms) from RGB images and estimated depth maps. We experimentally demonstrate and discuss the relationship between the central angle and the quality of digital holographic content.
AbstractBecause the Gompertz model has a long history of use as a population model, we analyzed its properties as a multistage stock‐recruitment model. We found that if a life‐cycle model is a sequence of linked Gompertz stock‐recruitment models at each life stage, then it is also a Gompertz stock‐recruitment model. This is similar to the well‐known result for the Beverton–Holt stock‐recruitment model. The Gompertz model is guaranteed to yield least squares estimates and therefore, can offer a distinct advantage over the Beverton–Holt model, which cannot be fit using linear regression and may not yield valid maximum likelihood estimates. We illustrate the use of this multistage modelling framework by applying it to Snake River spring/summer Chinook salmon (Oncorhynchus tshawytscha). We found that the Gompertz model fit the data better than the Beverton–Holt Model, and yielded similar carrying capacity estimates for both juveniles and adults. Past work by others on these populations has usually assumed that parr‐to‐adult survival is density independent. However, we found that this assumption may be incorrect: when we applied two‐stage models to these populations, we found density dependence at the juvenile‐to‐adult stage. This suggests that life‐cycle modelling to date has been overly optimistic about the benefits of survival rate increases in the hydro‐system and elsewhere to improve the viability of salmon populations threatened with high extinction risk.